Mechanical movement suitable for use as transmission for electric hair clippers



J1me 1950 c. VAN ARMBRUSTER ET AL ,8

MECHANICAL MOVEMENT SUITABLE FOR USE AS TRANSMISSION FOR ELECTRIC HAIR CLIPPERS Filed May 16, 1947 I 2 Sheets-Sheet l /9 JWMQQ 6 E1 21: EyZuz-zd June 6, 1950 c. VAN ARMBRUSTER ET AL MECHANICAL MOVEMENT SUITABLE FOR USE AS TRANSMISSION FOR ELECTRIC HAIR CLIPPERS 2 Sheets-Sheet 2 Filed May 16, 1947 I AMIGA-1% .Erw .Eylund C'eczZ vanfirmbrusizz i3 Patented June 6, 1950 USE HAIR CLIPPERS AS TRANSMISSION FOR. ELECTRIC Cecil Van Armbruster, New Holland, Pa., and Eric Bylund, Racine, Wis, 'assignors to 501111 Oster Manufacturing Company, Racine, a corporation of Wisconsin Application May 16, 1947, Serial :No. 74857- 3 Claims.

This invention relates to clippers and refers particularly to power driven hair clippers of the type wherein the rotary motion of a driving shaft is translated into reciprocation of the movable cutter blade.

Clippers of this type comprise essentially, a body which houses an electric motor, and at its forward end removably mounts a cutter head assembly consisting of cooperating stationary and movable cutter blades held assembled under spring tension, and drive means located within the forepart of the clipper body for translating rotation of the motor armature shaft into reciprocation of the movable cutter blade. To a large extent, the success of this type of clipper depends upon the drive mechanism between the armature shaft and the movable cutter blade, and it is, therefore, an object of this invention to provide an improved drive transmission for this purpose.

Another object of this invention is to provide a drive assembly for clippers of the character described which is silent in operation.

A further object of this invention is to pro- I vide a drive for clippers of the character described in which all force applying connections between driving and driven elements have substantial surface area to thus reduce wear to a minimum.

Another object of this invention is to provide a drive for clippers of the character described wherein the forces are applied in a balanced manner to thereby assuresmoother operation and a minimum of wear.

A still further object of this invention is to provide a drive .for clippers of the character described which is simple to produce and-.sufiicientlyrugged to withstand the relatively hard usage to which equipment of this type is subjected.

With the above and other objects in view which will appear as the description proceeds, this invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described, and more particularly defined by the appended claims, it being :understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

The accompanying drawings illustrate two complete examples "of the physical embodiment of the invention constructed in accordance with the best 'modes so fardevised for the practical application of the principles thereof and in which:

Figure 1 is a top plan view of the front end portion of a clipper having the drive transmission of this invention installed therein, said view having .a .part broken away and shown in section along the plane of line l-l of Figure :2;

Figure 2 essentially is a longitudinal sectional view through the front end of a @clipper embodying this invention;

Figure 3 is a perspective view of the major elements of the drive assembly shown separated and in their proper .order of assembly;

Figure 4 a horizontal sectional :view through the front end portion of a clipper illustrating a modified embodiment of this invention; and

Figure 5 is a longitudinal sectionalview through Figure 4 on a plane of line 55.

Referring particularly to the accompanying drawings, the numeral 5 designates the body of a power driven hair clipper which, as is customary, provides the housing for an electric :motor (not shown). The body 5 is generally molded from a suitable plastic. 'Its forepart 6 has a cavity 1 formed therein for the reception of the drive mechanism, indicated generally by the numera-l 8, by which'rotary motion of the armature shaft 9 of the motor is translated into reciprocation of a movable cutter blade ill. The movable blade In is held assembled with a cooperating stationary cutter blade ll by means of a spring l2. These parts comprise a removable cutter head "or assembly which is detachably secured "to the inclined front end of "the forepart 6 of the body by screws [3.

The cavity 1 has ahole '14 in its rear wall .[5 through which the armature shaft .9 protrudes and has a hole 16 initsfron't wall through which a driving lug l7 proiectsto have direct, though separable, driving connection with the movable cutter blade. .The driving lug 1.1 is an integral partof acrossheador yoke l.8, received within the cavity .7 and-constrained to reciprocation'cross Wise of the armature shaft :and parallel with the direction of reciprocatory movement of the movable cutter blade.

A guide pin 49 slidably received in a bore :29 in the crosshead and having its fiends anchored in =thezside walls 2 l :of the cavity :holds the "crosshead assembled with theiclipper body :and guides its 'movement. A=rib r22 projecting from the bottom of the crosshead or yoke :and "parallel to the guide pin slides on the bottom wall 1.3. of the cavity to i-limit-downward movement of vthe :front portionof the crossheadz or tyoke.

Upward-movement :of the crosshead for yoke.

about the guide pin 19 is prevented by the interpositioning of a worm gear 24 and an eccentric 25 between the yoke and a cover 26 for the cavity. The crosshead or yoke is thus constrained to translating motion crosswise of the clipper and parallel to the direction of reciprocation of the movable cutter blade.

The top of the crosshead or yoke is formed with two parallel spaced shoulders 21 and 28 perpendicular to the axis of the pin IS. The driving lug [1 projects forwardly from the part of the crosshead or yoke on which the shoulder 21 is located. The shoulders 21 and 28 have a block 29 snugly, though slidably, fitted therebetween. This block has a round hole 30 in which the eccentric 25 is received. Thus the block 29 serves as a motion transmitting connection between the eccentric and the crosshead or yoke, in which all force is transmitted through relatively large surfaces to minimize wear.

The eccentric 25 is fixed to the worm wheel 24 and both are journalled for rotation on a pin or shaft 3| anchored in the bottom wall 23 of the cavity. The shaft or pin 3| passes through a hole 32 in the crosshead or yoke which of course is large enough to permit reciprocation of the crosshead or yoke.

Rotation is imparted to the eccentric by a worm 33 fixed to the end of the armature shaft 9, and meshing with the worm wheel 24. Thus it will be seen that rotary motion of the armature shaft 9 is translated into reciprocation of the movable cutter blade in a manner which assures smooth noiseless operation.

Attention is specifically directed to the fact that the point at which force is applied by the eccentric to the crosshead or yoke, lies between the two sources of frictional drag resisting reciprocation of the crosshead or yoke. These are the sliding connections between the crosshead and the pin l9 and the sliding connection between the two cutter blades. By locating the point of connection between the eccentric and the crosshead or yoke between these two friction sources a smoother, more balanced distribution of forces, and consequently, a smoother quieter action is achieved.

At the point of egress of the driving lug H from the cavity 7, a suitable oil or grease seal 34 is provided. This seal may consist of a metal plate mounted to ride with the driving lug I! or a felt barrier may be substituted therefor.

In that embodiment of the invention shown in Figures and 5, the essential elements of the drive assembly are the same as those described, but in this case the advantageous balanced application of forces is not present. In this case the crosshead or yoke 35 is fixed to a guide pin 39 which is slidable in a transverse bore 31 in the forepart of the clipper body at opposite sides of the opening 38 in the front wall of the clipper body through which the driving lug 39 projects for engagement with the movable cutter blade. In this case the connection between the driving lug 39 and the cutter blade coacts with the guide pin 36 to constrain the crosshead or yoke to translating motion, the inner end of the crosshead or yoke being free from the surrounding walls of the cavity in which it is located.

The same manner of translating rotary motion of the drive shaft 9 into reciprocation of the crosshead is employed, that is, a worm gear rotating an eccentric and the eccentric acting through a flat-sided block received between parallel shoulders on the crosshead or yoke.

The passage of grease from the cavity through the opening 38 is prevented by a seal 40 closing those portions of the opening 38 not occupied by the driving lug 39.

From the foregoing description taken in connection with the accompanying drawings, it will be readily apparent that this invention provides a drive assembly for power driven clippers which assures smooth silent operation and reduces wear of the operating parts to a minimum.

What we claim as our invention is:

1. Transmission means for translating rotation from a power source into a reciprocating movement, comprising: a rotary drive shaft; a guide pin crosswise of the drive shaft; a crosshead slidably mounted on said guide pin for reciprocatory motion crosswise of the drive shaft, said guide pin constituting a source of frictional drag resisting reciprocation of the crosshead; a driving lug projecting from the crosshead at a point remote from its connection with the guide pin and adapted to subject the crosshead to a second source of drag when connected with a load to be reciprocated; a stub shaft mounted with its axis in normal relationship to the axes of the drive shaft and the guide pin and located between the guide pin and the path of the driving lug on the crosshead; an eccentric mounted on said stub shaft and drivingly connected with the crosshead between the guide pin and the path of the driving lug on the crosshead so that the application of reciprocatory force to the crosshead is along lines parallel to the guide pin but lying between said two sources of drag resisting reciprocation of the crosshead, whereby the tendency of the crosshead to bind upon the guide pin is minimized; and means drivlngly connecting the eccentric with the drive shaft.

2. Transmission means for translating rotation from a power source into a reciprocating movement, comprising: a substantially horizontal guide pin; a crosshead mounted on said guide pin for back and forth sliding motion lengthwise of the pin, the body of the crosshead extending horizontally and substantially entirely to one side of the guide pin and having a driving lug on its extremity remote from the guide pin; means on the upper portion of the crosshead defining a channel-like groove therein open at the top of the crosshead and extending transversely of the axis of the guide pin; an upright stub shaft passing through a hole in the body of the crosshead between the sides of said channel-like groove and located intermediate the guide pin and the path of motion of the driving lug on the crosshead; an eccentric mounted on said stub shaft and supported on the crosshead at the bottom of said channel-like groove; a drive block connected with the eccentric and slidably received in said channel-like groove for translating rotation of the eccentric into re ciprocatory motion of the crosshead on its guide pin, said drive block lying between the guide pin and the path of motion of the driving lug on the crosshead; and means at the upper portion of the eccentric for establishing a rotation transmitting connection between the eccentric and the power source.

3. Transmission means for translating rotation from a power source into a reciprocating movement, comprising: a crosshead; guide means at one end of the crosshead to guide the same for substantially horizontal reciprocatory motion; a driving lug on the opposite end of the crosshead; an upright stub shaft intermediate the guide pin and the path of motion of the driving lug, said stub shaft projecting through a hole in the crosshead to have its upper end project a distance above the crosshead; an eccentric mounted on the upper end of the shaft and supported on the top of the crosshead; means providing a driving connection between the eccentric and the crosshead by which rotation of the cocentric is translated into reciprocatory motion of the crosshead, said means being located intermediate the guide means and the path of movement of the driving lug on the crosshead; and means at the upper portion of the eccentric for establishing a rotation transmitting connection between the eccentric and the power source.

CECIL VAN ARMBRUSTER. ERIC BYLUND.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

